Not really interesting. Gaming is often stressful and requires more though / action being put into it. Also there is the matter of skill - it's way more fun to see someone completely anihilate the other team, than to go out and get killed yourself. You can also go through a story based game without having to actually play, and you get most of the experience. You also need to count in people watching other people's guides, especially for strategy games. For other hobbies it's often about actually doing something and feeling the rush, or by occupying the hands and chilling out. You don't get the rush of driving a car by watching someone else do it. You don't get your hands occupied by seeing someone knit. Also, gaming provides instant feedback / dopamine. Watching it does that with even less effort.